1. Field of the Invention
The present invention relates to an image forming device for forming an image on a photosensitive recording medium. The present invention particularly relates to an image forming device including a display panel for exposing a photosensitive recording medium to light.
2. Description of the Related Art
JP-A H07-304212 discloses an example of prior art image forming device. The prior art image forming device (digital printer) is designed to form an image on a photosensitive recording medium. Specifically, the printer includes an exposure unit, and an imaging unit arranged between the exposure unit and a photosensitive recording medium. The exposure unit comprises a transmissive liquid crystal panel and a backlight. The imaging unit comprises a lens, mirror and an aperture, for example.
In the prior art printer, image forming is performed as follows. Firstly, a pattern corresponding to an image to be formed is formed on the liquid crystal panel, and the pattern is illuminated by the backlight. The liquid crystal panel blocks part of the illuminating light but transmits the remaining part of the light. The transmitted light is converged on the photosensitive recording medium via the imaging unit, whereby an electrostatic latent image is formed on the recording medium. Finally, the electrostatic latent image is subjected to a developing process, whereby the intended image is provided as a visible image.
As noted above, in the prior art printer, the imaging unit is arranged between the exposure unit and the photosensitive recording medium. The existence of the imaging unit constitutes an obstacle to the reduction of thickness and weight of the entire printer.
Further, the prior art printer has a drawback that the light emitted from the exposure unit is weakened by passing through the imaging unit. Clearly, such attenuation of light (reduction in amount of light) is not favorable for forming a high quality image. Therefore, in the prior art printer, the amount of light to be emitted from the backlight is set to a relatively high level to compensate for the loss of light. However, such a measure causes another problem of an increase in power consumption of the printer.